Current carbon capture and storage (CCS) techniques focus on capture from large point sources. According to the Intergovernmental Panel on Climate Change (IPCC) report, about 60 percent of global carbon dioxide emissions from fossil-fuels are attributed to large stationary sources. Assuming 90 percent capture efficiency and 90 percent coverage of all sources, about 50 percent of global emissions would still be released into the atmosphere. This is far too much to allow for the stabilization of the atmospheric concentration of carbon dioxide and insufficient to constrain the growth of atmospheric carbon dioxide concentrations as the world economy grows.
Direct capture of carbon dioxide from ambient air was first suggested by Lackner et al. in 1999 as a method to counteract global warming. Energy requirement and cost analysis studies claim that air capture is feasible and economically viable. At the same time, the uncertainty in economic assessments for future air capture implementation is significant, considering technique and market development. Success will depend on a more energy efficient sorbent cycle.